118781409 has 4 divisors (see below), whose sum is σ = 158375216. Its totient is φ = 79187604.

The previous prime is 118781389. The next prime is 118781471. The reversal of 118781409 is 904187811.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 118781409 - 2⁸ = 118781153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (118781009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19796899 + ... + 19796904.

It is an arithmetic number, because the mean of its divisors is an integer number (39593804).

Almost surely, 2^118781409 is an apocalyptic number.

It is an amenable number.

118781409 is a deficient number, since it is larger than the sum of its proper divisors (39593807).

118781409 is an equidigital number, since it uses as much as digits as its factorization.

118781409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39593806.

The product of its (nonzero) digits is 16128, while the sum is 39.

The square root of 118781409 is about 10898.6884073268. The cubic root of 118781409 is about 491.5671179221.

The spelling of 118781409 in words is "one hundred eighteen million, seven hundred eighty-one thousand, four hundred nine".